New plastic membrane and carbon paste ion selective electrodes for the determination of triprolidine.

Triprolidine (Trip) ion selective electrodes of three types: the conventional polymer membrane (I), graphite coated electrode (II) and carbon paste electrode (III), have been prepared, based on the ion pair of triprolidine hydrochloride with sodium tetraphenylborate. The electrodes exhibit a linear response with a mean calibration graph slope of 56.12, 55.00 and 54.32 mV decade(-1) at 25 degrees C for I, II and III, respectively, within the concentration ranges 1.96 x 10(-5) - 1.00 x 10(-2) M for I and 3.84 x 10(-5) - 1.00 x 10(-2) M for II and III. The detection limits are 1.13+/-0.13 x 10(-5), 1.70+/-0.06 x 10(-5) and 1.78+/-0.05 x 10(-5) M for the three electrodes, respectively. The change of pH within the ranges 4.85 - 8.75 and 4.70 - 8.50 for I and III, respectively, did not affect the electrode performance. The standard electrode potentials were determined at different temperatures and were used to calculate the isothermal coefficient of the electrode. The electrodes showed a very good selectivity for Trip with respect to a large number of inorganic cations and compounds. The standard addition method was applied to the determination of TripCl in pure solution, pharmaceutical preparations, and urine samples.     

Construction and performance characteristics of new tetramisole selective plastic membrane electrodes

New tetramisole (Tm) ion selective PVC membrane electrodes are constructed based on either the ion-pair complex Tm TPB (Electrode I) where TPB is tetraphenylborate or the ion associate Tm(3) PT (Electrode II) where PT is phosphotungstate. The rectilinear concentration ranges of Electrodes I and II are 4 x 10(-5)-10(-2)M (average slope = 55.7 mV/concentration decade) and 5 x 10(-5)-10(-2)M TmCl (average slope = 57.0 mV/concentration decade), at 25 degrees C, respectively. The life time of the two Electrodes I and II are 14 and 49 days of continuous working, respectively. The change in pH does not affect the electrodes performance within the range 3.0-5.5, 3.0-6.0 and 3.0-7.0 for Tm concentrations 10(-2) 5 x 10(-3) and 10(-3)M, respectively. The isothermal coefficients of Electrodes I and II are found to be 0.000667 and 0.001164 V/ degrees C, respectively. The electrodes proved to be highly selective for TmCl towards inorganic cations, sugars and amino acids. The standard addition method and potentiometric titration are used to determine Tm in pure solutions and in tetramisole 10% oral solution. Regeneration process for the exhausted Electrodes I and II is applied successfully by soaking them in a solution of NaTPB and PTA, respectively.     

Copper(II) modified carbon paste electrodes based on self-assembled mercapto compounds-gold-nanoparticle

Three mercapto compounds [2-mercapto-5-(1-methyl-5-nitroimidazole-2-yl)-1,3,4-thiadiazole] (MMNIT), [2-mercapto-5-(5-nitrofuran-2-yl)-1,3,4-thiadiazole] (MNFT) and [2-mercapto-5-(5-nitrothiophen-2-yl)-1,3,4-thidiazole] (MNTT) were used for self-assembled-gold nanoparticle (SAGNP) modified carbon paste electrodes. The electrodes were applied as indicator electrodes for potentiometric determination of Cu(II) ion. The prepared electrodes exhibit a Nernstian slope of 31.0+/-0.5 mV per decade for Cu(II) ion over a wide concentration range of 7.9x10(-9)-3.2x10(-2), 7.9x10(-9)-7.9x10(-4), and 2.8x10(-8)-7.9x10(-3) mol L(-1) for MMNIT, MNFT and, MNTT, respectively. The detection limits of electrodes were 3.5 (+/-0.2)x10(-9), 4.1x10(-9), and 4.1x10(-8) mol L(-1) of copper ion, respectively. The potentiometric responses of electrodes based on MMNIT, MNFT, and MNTT are independent of the pH of test solution in the pH range 2.0-5.5, 2.5-7.0, and 2.0-6.5, respectively. They have quick response with response time of about 5 s. The proposed electrodes show fairly good selectivity over some alkali, alkaline earth, transition and heavy metal ions. Finally, the proposed electrodes were successfully employed to detect Cu(II) ion in hair and water samples.     

Flow injection analysis with tubular membrane ion-selective electrode and coated wires for buspirone hydrochloride

New Plastic membrane ion-selective electrode for buspirone hydrochloride based on buspironium tetraphenylborate was prepared. The electrode exhibited mean slope of calibration graph of 58.4 mV per decade of BusCl concentration at 25 degrees C. The electrode can be used within the concentration range 6.3 x 10(-5) - 10(-2) M BusCl at a pH range of 2.5-7.0. The standard electrode potentials were determined at different temperatures and used to calculate the isothermal temperature coefficient of the electrode, amounting to 0.00056 V degrees C(-1). The electrode showed a very good selectivity for BusCl with respect to a number of inorganic cations, sugars and amino acids. The electrode was applied to the potentiometric determination of the buspirone ion and its pharmaceutical preparation under batch and flow injection conditions. Also, buspirone was determined by conductimetric titrations. Graphite rod, copper and silver coated wire electrodes were prepared and characterized as sensors for the drug under investigation.     

Amineptine Plastic Membrane Electrode Based on its Ion Associate with Tetraphenylborate and Phosphomolybdic Acid

New amineptine hydrochloride (Am-Cl) ion-selective electrodes (conventional type) based on amineptinium-tetraphenylborate (I) and amineptinium-phosphomolybdate (II) were prepared. The electrodes exhibited mean slopes of calibration graphs of 57.9?mV and 53.8?mV per decade of (Am-Cl) concentration at 25?°C for electrodes (I) and (II), respectively. The electrodes can be used within the concentration range 3.16×10^?5?10^?2?M (Am-Cl) at a pH range of 2.0–3.9 for both electrodes. The standard electrode potentials were determined at different temperatures and used to calculate the isothermal coefficients of the electrodes, which were 0.00172?V?°C^?1 and 0.00091 V?°C^?1 for (I) and (II) electrodes, respectively. The electrodes showed a very good selectivity for (Am-Cl) with respect to a number of inorganic cations and sugars. The standard addition method is successfully applied to determine (Am-Cl) in pure solutions and in amineptine-containing tablets.     

Potentiometric determination of potassium cations using a nickel(II) hexacyanoferrate-modified electrode

Electroactive nickel(II) hexacyanoferrate (NiHCF) thin film modified electrodes are effective potentiometric sensors for the determination of potassium ions. The NiHCF films are deposited onto glassy carbon electrodes by repetitive potential cycling in K(3)Fe(CN)(6)/NaNO(3)/Ni(NO(3))(2) solution. The modified electrodes exhibit a linear response to potassium ions in the concentration range 1x10(-3) to 2.0 mol dm(-3), with a near-Nernstian slope (45-49 mV per decade) at 25 degrees C. In the determination of potassium ion in syrups used for treatment of potassium deficiency, the NiHCF-modified electrode gave comparable results to those obtained using flame emission spectrophotometry.     

Potentiometric determination of silver(I) by selective membrane electrode based on derivative of porphyrin.

The performance of silver metal complexes with meso-tetraphenylporphyrin ([H2T(4-CH3)]PP) as ionophores for ion-selective electrodes was studied. The electrode exhibited linear response with Nernstian slope of 59.2 +/- 1.0 mV per decade within the concentration range of 1.0 x 10(-7)-1.0 x 10(-1) M silver ions. The limit of detection as determined from the intersection of the extrapolated linear segments of the calibration plot, was 1.0 x 10(-7) M. The response time of the electrode was < 10 s over the entire concentration range. The silver-selective electrode exhibited good selectivity for Ag(I) with respect to alkali, alkaline earth and heavy metal ions. The electrodes could be used at least three months without a considerable divergence in their potential. The electrodes are suitable for use in aqueous solutions in a wide pH range of 3.0-9.0. They were used as indicator electrodes in titration of Ag(I) with sodium iodide solution and were successfully applied to direct determination of silver in real samples.     

Construction and analytical applications of plastic membrane electrode for oxymetazoline hydrochloride.

A new oxymetazoline (OM) ion-selective PVC membrane electrode based on the ion associate of OM with phosphotungstic acid was prepared. The electrode exhibits a linear response with a mean calibration graph slope of 57.16 mV decade(-1) at 25 degrees C within the concentration range of 1.96 x 10(-5) - 1 x 10(-2) M OMCl. The change in the pH within the range of 1.0 - 9.4 did not affect the electrode performance. The standard electrode potentials were determined at different temperatures and used to calculate the isothermal coefficient of the electrode (-0.001233 V). The electrode showed a very good selectivity for OM with respect to a large number of inorganic cations and compounds. The standard addition method and potentiometric titration were applied to the determination of (OM) with RSD not exceeding 1.19%.     

Nitrate-selective membrane electrode based on bis(2-hydroxyanil)acetylacetone lead(II) neutral carrier.

A nitrate-selective electrode based on a recently synthesized bis(2-hydroxyanil)acetylacetone lead(II) complex [(haacac)Pb] has been developed. Among different compositions studied, a membrane containing 30.7% poly(vinyl chloride) (PVC), 61.3% dibutyl phthalate (DBP) as a plasticizer, 3% methyltrioctylammonium chloride (MTOAC) as a cationic additive and 5% ionophore (all w/w) exhibited the best potentiometric response toward nitrate ion in aqueous solutions. The potentiometric response of the electrode was linear with a Nernstian slope of -58.8 mV decade(-1) within the NO3- concentration range of 2 x 10(-5)-1 x 10(-1) mol dm(-3). The response time of the electrode was < or =10 s over the entire linear concentration range of the calibration plot. The electrode is suitable for use within the pH range of 5.3-11. The selectivity coefficients for the proposed electrode were improved for some interferences, when compared with those of commercially available nitrate-selective electrodes.     

Mercury(II) ion-selective electrodes based on heterocyclic systems

Mercury ion-selective electrodes (ISEs) were prepared with a polymeric membrane based on heterocyclic systems: 2-methylsulfanyl-4-(4-nitro-phenyl)-l-p-tolyl-1H-imidazole (I) and 2,4-diphenyl-l-p-tolyl-1H-imidazole (II) as the ionophores. Several ISEs were conditioned and tested for the selection of common ions. The electrodes based on these ionophores showed a good potentiometric response for Hg2+ ions over a wide concentration range of 5.0 x 10(5-) - 1.0 x 10(-1)M with near-Nernstian slopes. Stable potentiometric signals were obtained within a short time period of 20 s. The detection limits, the working pH range of the electrodes were 1.0 x 10(-5) M and 1.6-4.4 respectively. The electrodes showed better selectivity for Hg2+ ions over many of the alkali, alkaline-earth and heavy metal ions. Also sharp end points were obtained when these sensors were used as indicator electrodes for the potentiometric titration of Hg2+ ions with iodide ions.     

A 9,10-anthraquinone derivative having two propenyl arms as a neutral ionophore for highly selective and sensitive membrane sensors for copper(II) ion.

New polymeric membrane (PME) and coated graphite (CGE) copper(II)-selective electrodes based on 1-hydroxy-2-(prop-2'-enyl)-4-(prop-2'-enyloxy)-9,10-anthraquinone were prepared. The electrodes reveal linear emf-pCu2+ responses over wide concentration ranges (1.0 x 10(-5)-1.0 x 10(-1) M with a slope of 27.3 mV decade-1 for PME and 8.0 x 10(-8)-5.0 x 10(-2) M with a slope of 29.1 mV decade-1 for CGE) and very low limits of detection (8.0 x 10(-6) M for PME and 5.0 x 10(-8) M for CGE). The potentiometric response is independent of the pH of the test solution in the pH range 3.0-6.0. The proposed electrodes possess very good selectivities over a wide variety of other cations, including alkali, alkaline earth, transition and heavy metal ions, the selectivity coefficients for the CGE being much improved over those for the PME. The electrodes were used as indicator electrodes in the potentiometric titration of Cu2+ and in the recovery of copper ions from wastewater.     

Papaverine PVC membrane ion-selective electrodes based on its ion-exchangers with tetraphenylborate and tetrathiocyanate anions

The construction and general performance of novel potentiometric membrane ion selective electrodes for determination of papaverine hydrochloride has been described. They are based on the formation of the ion association complexes of papaverine (PA) with tetraphenylborate (TPB)(I) or tetrathiocyanate (TTC)(II) counter anions as electro-active material dispersed in a PVC matrix. The electrodes show fast, stable, near Nernstian response for 1 x 10(-2) to 6 x 10(-5) M and 1 x 10(-2) to 1 x 10(-5) M for PA-TPB and PA-TTC respectively at 25 degrees C over the pH range of 3-5.0 with a cationic slope of approximately 56.5 +/- 0.5 mV/decade for both sensors respectively. The lower detection limit is 4 x 10(-5) and 8 x 10(-6) M for PA- I and PA-II respectively with fast response time ranging from 20-45 sec. Selectivity coefficients for PA relative to a number of interfering substances were investigated. There is a negligible interference from the studied cations, anions, and pharmaceutical excipients. The determination of 4.0- 3000.0 microg/ml of PA in aqueous solutions shows an average recovery of 99.1% and a mean relative standard deviation of 1.4 at 100microg/ml. The direct determination of PA in some formulations (Vasorin injection) gave results that compare favorably with those obtained using the British Pharmacopoeia method. Potentiometric titration of PA with sodium tetraphenylborate and potassium thiocyanate as titrants utilizing the papaverine electrode as an end point indicator electrode has been carried out.     

A liquid-state copper(II) ion-selective electrode containing a complex of Cu(II) with salicylaniline

A new liquid-state ion-selective electrode based on a complex of Cu(II) with salicylaniline is described. The electrode shows linear dependence of potential on the activity of Cu(2+) in the range from 5 x 10(-6) to 0.1M, with a slope of 28.3 mV/pCu at 18 degrees . The electrode shows a better selectivity relative to Ag(I) and Hg(II) than other copper(II) ion-selective electrodes. The possibilities for using the electrode for determination of copper in the presence of interfering cations are described.     

Triethylene glycol ether end-grafted carbosilane dendrimer: a potential ionophore for potassium ion recognition.

The performance of a newly synthesized carbosilane dendrimer bearing four triethylene glycol ether (TEG) units, Si(CH2CH2CH2Si(Me)2CH2CH2CH2(OCH2CH2)3Me)4 (1), as ionophores in ion-selective electrodes has been investigated. Optimization of the plasticized polyvinyl chloride membrane composition has produced electrodes that exhibit a Nernstian response for potassium ions. The best general characteristics exhibited by the electrodes were found when the membrane composition ratio of DPE:1:NaTPB:PVC 60:3:2:35 (wt%) was used. The response of the electrode was linear with a Nernstian slope of 58.3 mV/decade over the K+ ion concentration range of 1.9x10(-7) to 1.0x10(-1) M with a detection limit of 3.1x10(-7) M. The response time to achieve a 95% steady potential for the K+ concentration ranging from 1.0x10(-1) to 1.0x10(-8) M was less than 10 s, and it was found that the electrode is suitable for use within a pH range of 5.5-8.5. The selectivity coefficients (log KPotK+,Mn+)), which were determined by the fixed interference method, showed good selectivity for K+ against most of the interfering cations. The influence of this selective ion-binding behavior using electrospray ionization time-of-flight (ESI-TOF) mass spectrometric studies is discussed.     

Poly(vinyl chloride)-based macrocyclic membrane sensors for magnesium

Poly(vinyl chloride)-based membranes of macrocycles 4,11-dimethyl-2,4,9,11-tetraethyl-1,5,8,12-tetraaza cyclotetradeca-1,8-diene (I) and 4,11-dioxa-2,9-dimethyl-1,5,8,12-tetraaza cyclotetradeca-1,8-diene (II) with sodium tetraphenyl borate (STB) as an anion excluder and dibutyl phthalate (DBP), dioctyl phthalate (DOP), dibutylbutyl phosphonate (DBBP) and 1-chloronaphthalene (CN) as plasticizing solvent mediators were prepared and investigated as magnesium selective electrodes. The best performance was observed having the composition (II)-PVC-STB-DBP in the ratio 2:10:1:7, which works well over a wide concentration range (1.9x10(-6) to 1.0x10(-1) M) with a Nernstian slope of 29 mV per decade of activity between pH 2.5 and 6.5. These electrodes have been found to be chemically inert showing a fast response time of 15 s and were used over a period of 3 months with good reproducibility (S=+/-0.2 mV). The selectivity coefficient values for mono-, di- and trivalent cations indicate excellent selectivity for Mg(2+) over a large number of cations. The electrodes have also been used successfully in partially non-aqueous medium and as an indicator electrode in the potentiometric titration of Mg(2+) with EDTA. Anions such as Cl(-) and SO(4)(2-) do not interfere in the working of the electrode. The practical utility of the membrane sensor has also been observed in solutions contaminated with detergents (cetyltrimethyl ammonium bromide and sodium dodecyl sulphate). Above all, the membrane sensor has been very successfully used to analyse some babyfood products and soft drinks for the determination of Mg(2+).     

Flow injection potentiometric determination of pancuronium bromide in pharmaceutical preparation and urine samples using modified carbon paste electrodes

Carbon paste electrodes for pancuronium bromide was prepared based on ion association complexes of pancuronium bromide with sodium tetraphenylborate (NaTPB) or ammonium reineckate using dibutyl phthalate as solvent mediator and tetradodecylammonium tetrakis-(4-chlorophenyl)borate (ETH 500) as lipophilic additive. The sensors showed a near-Nernstian slope of 28.1 mV concentration decade(-1) at 25°C within the concentration range 6.31×10(-6)-1.00×10(-2) M in case of pancuronium-tetraphenylborate electrode and 26.6 mV concentration decade(-1) in the concentration range 5.66×10(-5)-1.00×10(-2) M in case of pancuronium-reineckate electrode. The sensors were successfully applied for the potentiometric determination of pancuronium bromide in pharmaceutical preparation and biological fluids in batch and flow injection conditions.     

双酰胺双(3'-正十五烷基-苯并-15-冠-5)PVC膜钾离子选择电极的研究

本文合成了十个双酰胺型双(3'-正十五烷基-苯并-15-冠-5)化合物, 制成的PVC膜钾离子选择电极, 性能优良.     

Liquid-membrane electrode sensitive to ammonia and aliphatic amines based on 1-[(2-oxyphenyl)iminomethly]-2-oxybenzene-O,O',N-ammin-nickel(II) complex

In this study, an ammonia-gas-sensing liquid-state membrane electrode based on 1-[(2-oxyphenyl)iminomethyl]-2-oxybenzene-O,O',N-ammin-nickel(II) (Ni(II)-Schiff base) as an ionophore was developed. This membrane electrode gave a very good performance and exhibited linear response with near-Nernstian slope of 50.7+/-0.5 mV per decade, within a concentration range of 1.0x10(-1)-1.0x10(-3) M. The electrode performance depends on the pH of the test solution and the optimum pH range was 10.0-11.5. The effect of concentration of internal solutions in the electrode was also investigated. The selectivity properties of the electrode towards aliphatic amines at a pH value of 10.2 were investigated with the mixed-solution method. Furthermore, the response time and lifetime of the electrode prepared were determined.     

A 15-crown-5-functionalized carbosilane dendrimer as ionophore for ammonium selective electrodes

The synthesis of CH(2)CHCH(2)OCH(2)[15-crown-5] (III) is achieved by the treatment of HOCH(2)- [15-crown-5] (I) with equimolar amounts of CH(2)CHCH(2)Br (II) in the presence of KOH. The hydrosilylation of III with Si(CH(2)CH(2)CH(2)SiMe(2)H)(4) (IV) in the presence of the Karstedt catalyst affords the crown ether end-capped carbosilane dendrimer Si(CH(2)CH(2)CH(2)Si-Me(2)CH(2)CH(2)CH(2)OCH(2)[15-crown-5])(4) (V). PVC-based membranes of V as ionophore with sodium tetraphenyl borate (NaTPB) as anion excluder and dioctyl phthalate (DOP), diphenyl ether (DPE), dibutyl amine (DBA) and dibutyl phthalate (DBP) as plasticizing solvent mediators were prepared and investigated as NH(4)(+)-selective electrode. The response of the electrode was linear with a Nernstian slope of 53.3mV/decade over an NH(4)(+) ion concentration range of 7.60x10(-6) to 1.0x10(-1)M and a detection limit of 3.9x10(-6)M. The response time to achieve a steady potential for NH(4)(+) ions was between 6 and 10s, and the electrode is suitable for use within the pH range of 2.2-8.5. The selectivity relative to alkali, alkaline earth, and transition heavy metal ions is good. The newly developed ionophore showed higher NH(4)(+) selectivity over K(+) ( [Formula: see text] ) and Na(+) ( [Formula: see text] ). The electrode could be used for at least 45 days without considerable alteration in its potential. The electrode also shows a better working concentration range and slope in comparison to other NH(4)(+)-selective electrodes reported in literature.     

Chemically modified carbon paste electrode for iodide determination on the basis of cetyltrimethylammonium iodide ion-pair.

A new carbon paste electrode (CPE) for the determination of iodide ion based on a cetyltrimethylammonium iodide (CTMAI) ion pair as an electroactive material is described. The electrode shows a linear response for iodide ion over the concentration range of 4 x 10(-5) M to 1 x 10(-1) M with a lower detection limit of 4 x 10(-5) M at 25 degrees C. The electrode has a Nemstian slope of -55.0 +/- 0.4 mV/decade and a fast potential response of 45 s, which is almost constant over a pH range of 5.0 - 9.0. Selectivity coefficient data of the CTMAI-CPE for some common ions show negligible interference, and the electrode has high selectivity towards the iodide ion. An average recovery of 101.83% with a relative standard deviation of 1.53% has been achieved for the determination of iodide in Flaxedil (gallamine triethiodide) ampoules, a muscle relaxant drug. The electrode has been examined for the determination of iodide in saline water; the results were found to compare favorably with those obtained using Metrohm iodide ISE. The electrode has been utilized as an end-point indicator electrode for the determination of Hg(II) and phenylmercury(I) in their aqueous solutions using potentiometric titration with a potassium iodide standard solution.